Abstract
Humans adapt to their environment through a unique amalgamation of culture and biology. Historically, it has long been presumed that across cultures, all humans perceive and sample the world in a comparable manner. Recently, however, this notion has been disputed by evidence showing fundamental perceptual differences between people from Eastern and Western cultures, for high- (e.g., faces) and low-level (e.g., reflexive saccades) visual information sampling strategies. Easterners perform global/central fixations towards the nose during face recognition and exhibit a larger number of low-latency express saccades. Westerners instead spread (local) fixations across the eye and mouth regions and execute significantly fewer low-latency express saccades. Yet, whether these well-established cultural differences are related to nature or nurture remains unaddressed. To address this issue, we recorded the eye movements of sixteen South Korean adults that were adopted in Switzerland during their firsts months of life, while they performed an old/new face recognition task and visually guided saccades. South Korean Adoptees (SKA) were culturally similar to Westerners, as measured by socio-cultural scales. For face recognition, the fitting results of a Bayesian model built from previous 2D cultural fixation data, objectively showed a clear-cut overlap between the SKA and the Western oculomotor distributions. Critically, the SKA also showed significantly fewer low-latency express saccades compared to Eastern observers, a profile once again comparable to Westerners. Our data show that nurture—not nature—is responsible for cultural variations in eye movements for faces and reflexive saccades. Crucially, these findings demonstrate that the oculomotor system is plastic enough to reverse cultural determinants in visual information sampling.
Meeting abstract presented at VSS 2016